Differential pressure cargo and luggage container



Sept. 19, 1961 J. L. BITTING DIFFERENTIAL PRESSURE CARGO AND LUGGAGE 2 Sheets-Sheet 1 Filed Feb. 6, 1959 INVENTOR. Jessa L. SITTING BY ATTORNEYS P 1961 J. L. BITTING 3,000,418

DIFFERENTIAL PRESSURE CARGO AND LUGGAGE Fi led Feb. 6, 1959 2 Sfieets-Sheet 2 ATTORNEYS UnitedStates Patent 3,000,418 DIFFERENTIAL PRESSURE CARGO AND LUGGAGE CONTAINER Jesse L. Bitting, Lake Charles, La. (29614 Crow Drive, Selfridge Air Force Base, Mich.) Filed Feb. 6, 1959, Ser. No. 791,724 6 Claims. (Cl. 150-52) This invention relates to cargo containers, carriers, or related load-retaining structures. More particularly, the invention has reference to a device of this nature that will be designed for containing and securing cargo, luggage, or any other objects upon any' type of vehicle.

To illustrate the invention, the container has been described and shown herein in the form of a device mountable upon the top of an automobile. However, it will be understood that this is merely exemplary of one form which the invention may take. In actuality, as will presently appear, the principles of the invention can be applied to containers used on aircraft, water craft, automobiles, trucks, etc. Obviously, the invention would differ in form according to the particular type of vehicle with which it is associated, all without, however, departure from the principles of the invention.

One important object is to provide a cargo and luggage container of the character described that will be so designed as to include an envelope having one or more flexible walls, said envelope being so designed as to perwit the same to be connected in communication with a source of vacuum, in a manner such as to cause said wall or walls to collapse about the confined object or objects, in such manner as to support and restrain the cargo over the greatest part of the surface area of the cargo. In this way, it is proposed that the invention will firmly hold the cargo in place upon a base incorporated in the container.

Another object is to incorporate in a container of the character described a base construction which, in at least one form of the invention, will be so designed as to incorporate a means of fastening the same firmly to the load-bearing structure of the vehicle. It is further proposed, in connection with the base, to provide a construction wherein in at least some installations, the base will conform itself in shape to the configuration of the surface with which the base is in contact, thus to distribute the weight of the supported load over the full area of the vehicle surface underlying said load, in a manner to avoid over-stressing of any one point of said surface such as would result from undue concentration of all the weight on a relatively small area.

Yet another object is to incorporate in the container a cover so designed as to completely enclose the cargo, in a water-proof and airtight envelope in which a vacuum or partial vacuum condition can be readily created.

Another object is to provide a container for luggage or other cargo which, though adapted in the manner described above to permit the swift creation of a vacuum condition therein, will nevertheless be designed to facilitate the swift opening and closing of the envelope.

Yet another object is to so design the device as to adapt the same for connection to a pre-existing source of vacuum. Thus, in automobile-top applications of the inven tion, it is proposed to permit the device to be communicated with the intake manifold of the automobile engine. When the invention is utilized in an aircraft, it is proposed to permit the device to be connected in communication with light-weight vacuum pumps such as are conventional equipment in many aircraft, with a secondary source of vacuum being obtainable by mounting a venturi in the slip stream or by tapping low pressure areas of the fuselage or wing surfaces.

Another object is to provide a device of the character stated that will be designed, in many applications of the invention, to permit full control of the vacuum introduced into the envelope, by means of a regulator or equivalent means adjustable to give a desired differential between ambient and inside pressures, ranging from zero differential up to and including the maximum of which the source of vacuum is capable.

Among other objects of the invention are the following:

To facilitate speed and ease of loading or unloading;

To adapt the differential pressure cargo and luggage container and carrier comprising the invention to almost any cargo (not of a liquid nature) capable of being confined in the envelope;

To permit differential pressure to be increased to provide more restraint for large heavy items, and to also permit the reduction of differential pressure when fragile items are being transported, in such a manner as to give firm restraint without damage;

To allow any shape of object to be accommodated, by reason of the fact that the cover conforms automatically to the shape of the confined load;

To so design the device that the retraint imposed upon the cargo against shifting or relative movement of the various pieces of the cargo, will be uniform or even over the entire surface of the cover and hence over the entire surface of the cargo, due to the fact that the restraint is produced by ambient pressure acting upon the outside of the cover, the arrangement being desirable in view of the characteristic thereof of eliminating pressure points which are ordinarily created by the use of hold-down ropes, cords, or straps;

To so design the device that it will make use of any of various available vacuum sources;

To provide a container as stated which will be characterized by economy in time, during the loading and unloading operations, as well as economy of manufacture;

To eliminate the use of wings, bolts, eyes, and equivalent devices ordinarily needed for tying down a cargo; and

To provide a device as stated which will occupy aminimum amount of space, by reason of the fact that because the cover collapses and folds about the cargo, the cargo and the container occupy the minimum possible cubage, resulting in substantial space savings when mounted inside a vehicle, as well as minimum clearance and aerodynamic drag when the device is mounted externally.

Other objects will appear from the following description, the claims appended thereto, and from the annexed drawings in which like reference characters designate like parts throughout the several views and wherein:

FIGURE 1 is a perspective view showing a conventional automobile fragmentarily, the container being illustrated in perspective as it appears when in use upon the vehicle;

FIGURE 2 is an enlarged transverse sectional view 1 on line 2-2 of FIGURE 1;

FIGURE 3 is a perspective view, on a scale between container 12 according to the present invention. At this point, it should be noted that a conventional automobile is shown, with the container being one that is specifically adapted for mounting On the top of the vehicle. However, while this will be one of the readiest applications of the invention, it should not by any means be considered as the only possible application of the construction. The

Patented Sept. 19, 1961 3 iny n icu could be used n or n a er mit. ire atti r other types of land vehicles besides the type shown in the drawing. According to the type of vehicle on which the dev ce. is used, h e e en m t empdified s are what. A a r The container 12 comprises uppen and lower'panhaped s s 5' a 1 e pe ti e Tue-l e Lion, 11 includes a bottom wall 14 which, in thecase of the container being for the top of the vehicle; would be semi-rigid so as to enable it; to conform, more or less, to the shape of the top oi the vehicle, as shown in FI UR a In the case of a custom installation, the bottom oi the unit might be made to fit exactly to the contour of the automobile top. This is not completely essentialfto suc-v cessful operation of the invention, however, and; any construction which would permit the base" portion to conform itself or be readily coniormed by a; user to the e e h pe o e h cn l -be omp e e y eds quate for its intended purposes.

a In. i li o e arrangements, as m ht e ri id y constructed, and might even consist wholly onin of; one or more surfaces of the load-carrying vehicle'itself;

I The cover section 15 comprises; a flexible; top wall: 18 a flexible depending peripheral wall which includes side walls 22 and 22' and end walls 21', and a sealing flap 21 extends around theperipheral wall, except forthe side wall'22', at the inward sideof the peripheral wall and extends therebelow and telescopes into-the lower section 11.

The lower section 11 which is pan-shaped and rectan; includes a bottom wall 14 and has aniupstanding flexible peripheral wall rising therefi'om, the flexible wall including side, walls 16 and 16 and'end walls 17' The side walls 16 and 16' have inwardly-directed flangeson the lower edges which are secured sealably" to; the periphery of the bottom wall 14. a

-In the illustrated device, closuremeans is provided, said closure means comprising a slide-fastener 20; which extends along the top of the side wall 16 andalongboth end walls 17'.

;Any of various suitablemeans can bezemployed-for connecting the container upon a vehicle. Ina car-top application, such as shown, such means comprises retain-- ing hooks 24 engageable with the rain gutters at the opposite sides 26 of the vehicle. Connected to the hooks 24 are straps 28, having buckles 30 incorporated therein to facilitate adjustment of the length of the straps, the straps being secured to the side walls 16 and 16' ofrthe lower section 11. e

The cover is adapted to be connected in communica-- tion with a readily available source of vacuum. Accord-. ingly, in the car-top application of the invention there is provided a line generally designated 32 extending from the lower section 11 of the container to the. intake mani-= fold 38 of the engine E of the vehicle. Line 32 is flexible fi'om end to end, and comprises a pair of tubes 34 and 36 connected to the lower container section 11 and to the intake manifold 38 of the vehicle engine E.

Connected in line 32 is anadjustable pressure regulas tor 40. For example, if fragile objects are'carried in the container 12, it would be desirable that the container collapse about such articles rather gently, rather than with a strong confining force. 'In this event al-partial vacuum is produced within the container which is on the order of only a half-pound less in pressure thanthe external atmospheric pressure upon the outer surtaceof the container. greater vacuum is produced within thekcontainer; As, a result, outside pressure upon the container ,causesthe cover to be collapsed into firm restrainingengagement' with the confined cargo C in'the container.

;'I he illustrated regulator 40 includes a shallowly-dished. or concave-convex lower casing section'42 .dis'posedin opposing relation to asimilar upperlcasing sectionAsl;

Where stronger objects are carried; a

4 r, e as ng ons. ha e. pe phe al flan e 1 which r secured together as by bolts 43. A diaphragm 46 extends across the casing with its edge engaged between the flanges 41 of the casing sections, defining at one side of the diaphragm a chamber a, while defining at the opposite side of the diaphragm a chamber b.

Centrally formed and extending downwardly from the a lower casing section 42 is a hollow boss 48 terminating in a fitting 49 connectable to the suction tube 36. A plug 50 having a dual valve seat is secured in the upper end of the boss 48. A spring-pressed ball valve 52 is engaged withthe lower one of the dual valve seats of the plug 50.

Adjacent boss 48 there is secured to the lower casing section 42 a fitting 54 'to which is connected the suction tube 34. e v

A plunger valve 56 is secured to the'diaphragm 46' and is normally spaced'from the upper end of the seat 50 by the diaphragm.

In the upper casingsection 44 there are formed vents 58 providing continuous communication between the interior of the'charnber b and outside Eh'gid with the'center' of the upper casing section 44 is an upstanding threaded tubular boss 60 on which is threaded a flat circular knurled nut 62; Spaced from the outer end of the boss and nut 62 is a spring cap 64, and a coil spring, circumposed about the boss 60, iscompressed between the boss and'the nut. Obviously, the tension of thespring'canrbe' adjusted for purposes to be made presently apparent by turning. the nut 62 along the boss 60.

,Reciprocable in the boreof the boss 60 he stem 68, the outer end of which carries the spring cap '64, and the inner end of which is connected'to the conically-tipped P un Air is evacuated from'the container 12 and enters the regulator 40 at the intake fitting 54. 'The' air passes through chamber a through the plugSO, past the unseated ball valve 52 to the tubeand thence to the manifold 38. The ball valve 52 is only lightly'loaded by a spring 70, the tension of the spring being only great enough in a static condition to hold the'checkball against the adjacent valve seat of the plug 50.

Initially, the vacuum in' the'diaphragm chamber a remains low, due to thelarg'e volume of air passing in through the vacuum outlet: fitting 54. As the air is evacuated from envelope 12 and pressure in the envelope decreases, the lower'pressure is communicated to the vacuum chamber a through'the vacuum outlet fitting 54; As the pressure in the diphragm chambera decreases, ambient pressure enters the regulator through the vents 58, and acts upon that surface of diaphragm 46 shown as the upper surface in FIGURE 4, this being the surface bounding, chamber b.

As the pressure ditferential increases, diaphragm is deflected in'a direction toward the boss'48, that is, downwardly, in FIGURE 4. This moves stem 68 in a corresponding direction, together with" the plunger or 'valve element 56. Spring66; meanwhile, is placed under increased compression by the mentioned movement of the stem 68.

When the'vacuumin' the envelope'and in the diaphragm chamber a has reached 'a predetermined value, the difierential pressure will have 'moved diaphragm 46, stem '68, and valve element or plunger 56 downwardly in FIGURE 4 to such an extentas to cause the valve element 56 to seat upon the-adjacent valve seat of plug 50, this being'th'e upper valveseat' of said plug viewing a the same as in FIGURE-4.

This closes oi the vacuum source, and allows the pressure differential on both the diaphragm chamber a and envelope 12 to remain at the predetermined value, which value can be determined inadvance by'selective adjustment of the tension of the spring-66 through the provision of the nut or abutment 62;

Once the pressuretdifierential has been established,

the vacuum source is closed olf and no air flow is allowed. If, then, vacuum in the envelope 12 should decrease due to leakage in the envelope or in the vacuum line, the vacuum in the diaphragm chamber a will also decrease. The tension of the spring 66 overcomes the lower pressure differential on the diaphragm 46, cansing the diaphragm to be deflected in a direction upwardly in FIGURE 4, thus to lift the valve element 66 off its associated valve seat. This opens the vacuum source to reestablish the desired pressure ditferential.

It will thus be seen that if a leak in the envelope does develop, air flow will be allowed by the regulator, but only in the exact volume necessary to compensate for the leak.

It will also be observed that the check ball 52 has been located at the down-stream side of the regulator, since it might cause a certain amount of restriction, which would be undesirable on the up-stream side of the regulator. To obtain the optimum operational characteristics and sensitivity, the passages up-stream of the regulator, that is, between the regulator 40 and the envelope 12, should be of uniform size and completely free of obstructions or restrictions.

The valve, when operating, will have a slight diiference in opening and closing pressures. For example, the valve might close at a differential pressure of 4" Hg, but would not reopen until pressure dropped to 3.85" Hg. This feature is desirable in that it will prevent chattering during operation. It may be noted that the feature comes into operation, and is controllable, by the area of the orifice of the double valve seat in the plug 50. Thus, when the valve closes, the maximum vacuum available at the source will be eifective on the area of the valve exposed by the orifice, thus adding slightly to the closing force. This of course would require a very slight drop in vacuum on the diaphragm surface before opening would occur.

As previously mentioned, this effect is desirable, to prevent overwork and valve chatter, and can be controlled easily by designing either a larger or smaller valve and seat as desired.

As to the relief of vacuum within the envelope prior to opening, this might be done in several ways, including a small bleed valve between ambient pressure and the valve chamber a. However, this should not be done by unseating of the check ball, it may be noted, particularly when an intake manifold is the source of vacuum. Were the check ball unseated under these conditions and for this purpose, there could be caused a drawing of the fuel-air mixture out of the manifold and into the envelope 12 It will be seen that by reason of the operational characteristics described above, when the device goes into operation the side, top, and end walls of the envelope or container 12 will collapse about and will conform very closely to the shape of the cargo C in the manner shown to particular advantage in FIGURES 1 and 2. In this way, a restraining force is immediately exerted upon the cargo, tending to hold the same in place upon base portion 14 without danger of shifting. Further, any tendency of the cover to flap in the wind during movement of the vehicle, in circumstances that would obviously create a weakening of the cover, is eliminated. Still further, aerodynamic drag is reduced to a minimum.

It is believed apparent that the invention is not necessarily confined to the specific use or uses thereof described above, since it may be utilized for any purpose to which it may be suited. Nor is the invention to be necessarily limited to the specific construction illustrated and described, since such construction is only intended to be illustrative of the principles, it being considered that the invention comprehends any change in construction that may be permitted within the scope of the appended claims.

What is claimed is:

1. In combination, a motor vehicle having a body and an engine-driven source of suction, a closed collapsible cargo container mounted on said body, a suction conduit leading from said source to the container, and an adjustable suction regulator connected in said conduit.

2. In combination, a motor vehicle having a body and an engine-driven source of suction, a closed collapsible cargo container mounted on said body, a suction conduit leading from said source to the container, and an adjustable suction regulator connected in said conduit, said source being an engine intake manifold.

3. In combination, a motor vehicle having a body top and an engine-driven source of suction, a flexible and collapsible closed container resting upon and conforming to the contour of said body top, and a suction conduit leading from the container to the suction source.

4. In combination, a motor vehicle having a body top and an engine-driven source of suction, a flexible and collapsible closed container resting upon and conforming to the contour of said body top, and a suction conduit leading from the container to the suction source, said source being an intake manifold of the engine, and a suction regulator connected in said conduit.

5. A dilferential pressure container comprising panshaped lower and upper sections, said lower section having a bottom wall and an upstanding flexible peripheral wall, said upper section having a flexible top wall and a flexible peripheral wall, said peripheral walls having end walls and first and second side walls, said walls having free edges, a flexible sealing flap secured to the inward side of the peripheral wall of the upper section to telescope into the lower section when the upper section is closed onto the lower section, means sealingly hinging the sec- 0nd side walls of the section together, separable fastening means along the free edges of the walls of the sections, a suction conduit leading into the interior of the container, and means secured to the lower section for securing the container on a support.

6. In combination, a vehicle body having a top, a differential pressure container comprising pan-shaped lower and upper sections, said lower section having a bottom wall and an upstanding flexible peripheral wall, said upper section having a flexible top wall and a flexible peripheral wall, said peripheral walls having end walls and first and second side walls, said Walls having free edges, a flexible sealing flap secured to the inward side of the peripheral wall of the upper section to telescope into the lower section when the upper section is closed onto the lower section, means sealingly hinging the second side walls of the section together, separable fastening means along the free edges of the walls of the sections, a suction conduit leading into the interior of the container, and means secured to the lower section for securing the container on the body top with the bottom Wall of the lower section resting upon the body top.

References Cited in the file of this patent UNITED STATES PATENTS 556,217 Shiels Mar. 10, 1896 2,073,290 Teague Mar. 9, 1937 2,331,297 Bendix Oct. 12, 1943 2,426,195 Geraci Aug. 26, 1947 2,795,257 Cunningham June 11, 1957 2,937,774 Roberts May 24, 1960 FOREIGN PATENTS 1,147,612 France Nov. 27, 1957 

